Aluminum alloy have outstanding advantages such as low density, high strength and corrosion resistance. It is widely used in industrial
equipment and daily consumer goods, especially in the currently popular new energy battery industry. The shell and cover of lithium batteries
use a lot of aluminum alloy. In the production process of lithium batteries, in order to control the production quality, it is necessary to trace the
entire production information, including incoming material information, production process, product batch, production manufacturer, date, etc.
The key information needs to be stored in the QR code and marked on the battery shell.
Application background of laser coding of new energy batteries
The traditional surface marking methods of aluminum alloys mainly include inkjet marking, mechanical etching and electrochemical corrosion.
The graphics of inkjet marking are easy to wipe and damage, and the information is easy to be deliberately tampered with. The graphics of
mechanical etching cannot be modified once etched. If an error occurs, the material must be recycled and processed as a whole, which is not
conducive to production in terms of cost. It is difficult to accurately control the degree of etching during electrochemical marking and
preservatives need to be removed, which is also very polluting to the environment. Laser marking has the characteristics of strong
permanence, high anti-counterfeiting, high precision, strong wear resistance, safety and reliability, and is the best solution for QR code
traceability.
Introduction to coding application characteristics and laser recommendation
QR code is also called two-dimensional barcode. Common QR codes include Data Matrix and QR Code. QR code is a more advanced
barcode format rather than one-dimensional code. One-dimensional code can only express information in one direction (generally horizontal),
while QR code can store information in both horizontal and vertical directions. One-dimensional code can only be composed of numbers and
letters, while QR code can store information such as Chinese characters, numbers and pictures, so the application field of QR code is more
extensive.
Raycus 20/30/50Qmini nanosecond pulse fiber laser has the characteristics of smaller size, lighter weight, maintenance-free, higher reliability
and better beam quality. Compared with traditional lasers, the power instability at rated power is ≤±1.5%. 20/30/50Qmini nanosecond pulse
fiber laser can be widely used in marking processing in new energy, 3C and hardware industries.
New energy battery coding application test
To mark a QR code, you first need to ensure that the overall outline of the QR code is clear, which can be achieved by adjusting the light-on
delay and light-off delay. Since the laser-marked QR code is formed by the overlap of several single-pulse light spots, the galvanometer
scanning speed and the laser repetition frequency jointly determine the overlap rate of the light spots. Only when a certain light spot overlap
rate is achieved under the appropriate parameter combination can a QR code with a certain grayscale or color be marked. Therefore, before
conducting a QR code marking test, you must first find the appropriate scanning speed, repetition frequency, fill line spacing and other
parameters
Summary
Currently, the most efficient way to mark a QR code on the battery cover is to mark a QR code with a white effect. The advantage of Raycus
20/30/50Qmini laser is that the marking time is short, which can meet the processing of 8mm*8mm QR codes within 1 second. And the reading
efficiency and reading success rate are high, which meets the beat of high-speed production lines.
Fill line spacing is an important factor affecting processing efficiency. The smaller the fill line spacing, the more lines are repeatedly arranged in
the same graphic area, and the longer the processing time. If the fill line spacing is too large, it is impossible to get enough spot overlap. After
experimental analysis, it was found that the filling line spacing of 0.05 mm is the most suitable parameter under the premise of satisfying
processing efficiency.
As the power increases, the color of the QR code gradually becomes whiter, and the QR code becomes fuller.